U.S. patent application number 12/888601 was filed with the patent office on 2011-03-31 for hair remover.
This patent application is currently assigned to Panasonic Electric Works Co., LTD.. Invention is credited to Toshio Ikuta, Kazuhiro Morisugi.
Application Number | 20110072669 12/888601 |
Document ID | / |
Family ID | 43334516 |
Filed Date | 2011-03-31 |
United States Patent
Application |
20110072669 |
Kind Code |
A1 |
Morisugi; Kazuhiro ; et
al. |
March 31, 2011 |
HAIR REMOVER
Abstract
A hair remover including an outer blade and an inner blade
accommodated in the outer blade. The outer blade includes a
cylindrical side wall, an upper wall, and a bend connecting the
side wall and the upper wall. Straight upper cutting edges and side
cutting edges are formed by slits extending from the upper wall to
an upper part of the side wall. The inner blade includes a straight
upper cutting edge, which is formed at a location corresponding to
the upper cutting edges of the upper blade, and a straight side
cutting edge, which is formed at a location corresponding to the
side cutting edges of the outer blade. The outer blade and the
inner blade are formed so as to clip body hair through cooperation
between the straight side cutting edges and cooperation between the
straight upper cutting edges.
Inventors: |
Morisugi; Kazuhiro;
(Inukami, JP) ; Ikuta; Toshio; (Hikone,
JP) |
Assignee: |
Panasonic Electric Works Co.,
LTD.
Osaka
JP
|
Family ID: |
43334516 |
Appl. No.: |
12/888601 |
Filed: |
September 23, 2010 |
Current U.S.
Class: |
30/29.5 |
Current CPC
Class: |
B26B 19/148
20130101 |
Class at
Publication: |
30/29.5 |
International
Class: |
B26B 19/00 20060101
B26B019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 25, 2009 |
JP |
2009-220454 |
Claims
1. A hair remover comprising: an outer blade; a drive source; and
an inner blade accommodated in the outer blade, the inner blade
being rotatable by the drive source to clip body hair in
cooperation with the outer blade; the outer blade including: a
cylindrical side wall; an upper wall; a bend connecting the side
wall and the upper wall; and straight upper cutting edges and
straight side cutting edges formed by a plurality of slits
extending from the upper wall to an upper part of the side wall;
and the inner blade including a straight upper cutting edge, which
is formed at a location corresponding to the upper cutting edges of
the upper blade, and a straight side cutting edge, which is formed
at a location corresponding to the side cutting edges of the outer
blade; wherein the outer blade and the inner blade are formed so as
to clip body hair through at least cooperation between the straight
side cutting edges and cooperation between the straight upper
cutting edges.
2. The hair remover according to claim 1, wherein the upper cutting
edges of the outer blade and the inner blade each extend straight
and perpendicular to a rotation axis of the inner blade.
3. The hair remover according to claim 1, wherein the outer blade
includes an even number of the slits that are arranged at equal
angular intervals.
4. The hair remover according to claim 3, wherein the outer blade
includes eight of the slits.
5. The hair remover according to claim 1, wherein the upper cutting
edge of the inner blade is discrete from the side cutting edge of
the inner blade.
6. The hair remover according to claim 1, wherein the upper wall is
flat; the outer blade includes a plurality of teeth defined by the
slits, each tooth including: a basal portion extending upward
substantially parallel to a center axis of the outer blade; a
distal portion extending inward toward the center axis of the outer
blade; and a curved bent portion located between the basal portion
and the distal portion; and wherein the upper cutting edges of the
outer blade are formed on the distal portions of the teeth; and the
side cutting edges of the outer blade are formed on the basal
portions of the teeth.
7. The hair remover according to claim 6, wherein the inner blade
further includes a relief formed at a location corresponding to the
bend of the outer blade, the relief of the inner blade is free from
contact with the outer blade, and the inner blade is in contact
with the outer blade only at straight portions including the upper
cutting edge and the side cutting edge.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from prior Japanese Patent Application No. 2009-220454,
filed on Sep. 25, 2009, the entire contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to a hair remover for trimming
body hair such as nose hair.
[0003] Japanese Laid-Open Patent Publication No. 7-313241 describes
a prior art example of a nose hair trimmer. The nose hair trimmer
includes an outer blade, which is cylindrical and suitable for
insertion into a nostril, and an inner blade, which is accommodated
in the outer blade. The inner blade is driven and rotated by a
drive source. The nose hair trimmer clips nose hair between the
stationary outer blade and the rotating inner blade. In the nose
hair trimmer of the prior art, the outer blade includes a plurality
of teeth, which are bent so as to be curved. Each tooth has a
curved outer blade cutting edge formed on each of its two lateral
sides. The inner blade includes an inner blade cutting edge, which
is curved in conformance with the outer blade cutting edges.
Rotation of the inner blade slides the inner blade cutting edge
along the outer blade cutting edges. This clips the user's nose
hair, which are received in slits of the outer blade, between the
cutting edges of the outer blade and the inner blade.
[0004] It is desirable for the nose hair trimmer to have a high
clipping capability. To improve the clipping capability, the number
of cutting edges in the outer blade and the inner blade may be
increased. However, when each blade has more cutting edges, this
tends to increase noise during use of the nose hair trimmer.
[0005] For example, in the nose hair trimmer of the prior art, the
outer blade and the inner blade each have an upper portion that is
bent so as to be curved. However, it is difficult for the bent
shape (curved shape) of the top portions to be in conformance
between the outer blade and the inner blade. This may increase
interference between the outer blade and the inner blade and
thereby increase noise. Further, due to the difficulty for
conformance in the curved shapes of the outer blade and the inner
blade, there may be locations at which the pressure applied by the
inner blade to the outer blade is insufficient. At such locations,
nose hair may not be clipped in a satisfactory manner.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a hair
remover that is quiet and has an increased clipping capacity.
[0007] One aspect of the present invention is a hair remover
including an outer blade, a drive source, and an inner blade
accommodated in the outer blade. The inner blade is rotatable by
the drive source to clip body hair in cooperation with the outer
blade. The outer blade includes a cylindrical side wall, an upper
wall, a bend connecting the side wall and the upper wall, and
straight upper cutting edges and straight side cutting edges formed
by a plurality of slits extending from the upper wall to an upper
part of the side wall. The inner blade includes a straight upper
cutting edge, which is formed at a location corresponding to the
upper cutting edges of the upper blade, and a straight side cutting
edge, which is formed at a location corresponding to the side
cutting edges of the outer blade. The outer blade and the inner
blade are formed so as to clip body hair through at least
cooperation between the straight side cutting edges and cooperation
between the straight upper cutting edges.
[0008] Other aspects and advantages of the present invention will
become apparent from the following description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention, together with objects and advantages thereof,
may best be understood by reference to the following description of
the presently preferred embodiments together with the accompanying
drawings in which:
[0010] FIGS. 1(a) and 1(b) are perspective views showing a nose
hair trimmer according to one embodiment of the present
invention;
[0011] FIG. 2 is a cross-sectional view showing the nose hair
trimmer of FIG. 1;
[0012] FIG. 3 is a perspective view showing an outer blade block
and inner blade block of the nose hair trimmer of FIGS. 1(a) and
1(b);
[0013] FIG. 4(a) is an exploded perspective view showing the outer
and inner blade blocks of FIG. 3;
[0014] FIG. 4(b) is an enlarged partial view of an inner blade
shown in FIG. 4(a);
[0015] FIG. 5 is a cross-sectional view of a blade unit;
[0016] FIG. 6 is a plan view of the blade unit;
[0017] FIG. 7 is a schematic diagram illustrating a process for
forming slits in the outer blade;
[0018] FIG. 8 is a perspective view showing a first modification of
the inner blade block;
[0019] FIG. 9 is a perspective view showing a second modification
of the inner blade block; and
[0020] FIGS. 10(a) to 10(d) are cross-sectional diagrams showing
reliefs in different modifications.
DETAILED DESCRIPTION OF THE INVENTION
[0021] A nose hair trimmer serving as a hair remover according to
one embodiment of the present invention will now be discussed with
reference to the drawings.
[0022] As shown in FIGS. 1(a) and 1(b), the nose hair trimmer
includes a blade unit 1 and a main body 2, which is coupled to the
bottom end of the blade unit 1. The main body 2 includes a handle
2a and a switch 3, which is arranged in the upper side of the
handle 2a and operated by a user to activate and deactivate the
nose hair trimmer. In the illustrated example, the nose hair
trimmer is cylindrical but slightly bent. This shape allows for the
user to easily insert the outer blade 11 into the nostril while
holding the handle 2a upright.
[0023] Referring to FIG. 2, a motor 4 serving as a drive source is
accommodated in the main body 2. The motor 4 includes a motor shaft
4a, which is coupled by a joint 5 to an inner blade block 20. When
the switch 3 is turned on, a battery (not shown), which is
accommodated in the handle 2a at the lower part of the main body 2,
drives the motor 4. When the motor 4 is driven, the motor shaft 4a
and joint 5 rotate the inner blade block 20. In this manner, the
blade unit 1 clips the user's nose hair (body hair).
[0024] As shown in FIG. 3, the blade unit 1 includes an outer blade
block 10 and an inner blade block 20.
[0025] Referring to FIGS. 3 and 4, the outer blade block 10
includes an outer blade 11, which has a cylindrical side wall 11a
and an upper wall 11c, and an outer blade frame 12, which is hollow
and shaped as a truncated cone. In the outer blade 11, a curved
bend 11b connects the side wall 11a and upper wall 11c. The upper
part of the side wall 11a and the upper wall 11c are partially open
by a plurality of slits 11d (refer to FIG. 6), which are extended
in the radial direction and arranged at equal angular intervals.
The outer blade frame 12 holds the basal end, or lower end, of the
outer blade 11. The outer blade frame 12 mounts the outer blade
block 10 onto the main body 2 in a removable manner. In the
illustrated example, the upper wall 11c is circular and flat.
Further, the term cylindrical includes tubular and tapered tubular
shapes.
[0026] Outer blade cutting edges will now be described. As shown in
FIG. 5, in the outer blade 11, the upper wall 11c includes upper
cutting edges 11e, and the side wall 11a includes side cutting
edges 11f. The bend 11b is located between the upper cutting edges
11e and the side cutting edges 11f. Each of the upper cutting edges
11e and side cutting edges 11f are straight. The outer blade
cutting edges cooperate with inner blades 21, which will be
described later, to clip nose hair that are received in the slits
11d. The upper cutting edges 11e extend straight and orthogonal to
the rotation axis L1 of the inner blade block 20 (motor 4). This
facilitates formation of the outer blade 11. As shown in FIGS. 3
and 4, the upper cutting edges 11e and side cutting edges 11f have
outer rims 11g that are preferably chamfered. The chamfering allows
for smooth insertion of the outer blade 11 into the nostril.
[0027] In the illustrated example, the outer blade 11 has eight
slits 11d. When there are eight slits 11d, this ensures that the
slits 11d have a width W2 that is suitable for receiving nose hair
(refer to FIG. 6), while the outer blade 11 is held with its
diameter remaining suitable for insertion into a user's nostril.
Thus, nose hair is effectively clipped when there are eight slits
11d. In addition, as shown in FIG. 7, when the outer blade 11 has
an even number of slits 11d arranged at equal angular intervals, a
disk-shaped grindstone 13 may be moved past the center of the
circular upper wall 11c of the outer blade 11, which is
cylindrical. This allows for two slits 11d to be formed at the same
time during a single passage of the grindstone 13 and thus shortens
the formation time of the slits 11d.
[0028] The inner blade block 20 will now be described. Referring to
FIGS. 3 to 5, the inner blade block 20 includes the inner blades
21, an inner blade frame 22, a sideward pushing spring 23, and an
upward pushing spring 24. The sideward pushing spring 23 pushes the
inner blades 21 against the side wall 11a of the outer blade 11.
The upward pushing spring 24 pushes the inner blade 21 against the
upper wall 11c of the outer blade 11. In the illustrated example,
the two inner blades 21 of the inner blade block 20 have the same
structure. There may be just one inner blade 21 or a plurality of
inner blades 21. One of the inner blades 21 will now be
described.
[0029] The inner blade 21 may be planar. The inner blade 21
includes a straight upper cutting edge 21a, which corresponds to
the upper cutting edges 11e of the outer blade 11, and a straight
side cutting edge 21b, which corresponds to the side cutting edges
11f of the outer blade 11. When the motor 4 drives and rotates the
inner blade block 20, the upper cutting edges 11e of the outer
blade 11 cooperate with the upper cutting edge 21a of the inner
blade 21 and the side cutting edges 11f of the outer blade 11
cooperate with the side cutting edges 21b of the inner blade 21 to
clip the nose hair received in the slits 11d. The straight cutting
edges 11e, 11f, 21a, and 21b allow for the shapes of the outer
blade 11 and the inner blade 21 to be in conformance more easily
than when they are curved. This decreases interference between the
outer blade 11 and the inner blade 21 that would be caused when the
outer blade 11 and inner blade 21 are not shaped in conformance.
Further, the production of noise is suppressed. In addition, the
pressure applied by the inner blade 21 to the outer blade 11
becomes stable and allows for satisfactory clipping of nose hair.
This improves the clipping capability.
[0030] The upper cutting edge 21a of the inner blade 21 extends
straight and orthogonal to the rotation axis L1 of the inner blade
block 20. Further, the straight upper cutting edge 21a facilitates
formation of the inner blade 21 and simplifies contact of the inner
blade 21 with the outer blade 11.
[0031] The inner blade 21 includes a tetragonal cutout portion, or
relief 25, at a location corresponding to the bend 11b of the outer
blade 11. Due to the relief 25 in the inner blade 21, the outer
blade 11 and inner blade 21 contact each other only at straight
portions and do not contact each other at curved portions. This
effectively suppresses the production of noise and prevents
incomplete clipping of the nose hair that may occur at curved
portions.
[0032] As shown in FIG. 4(b), a corner 21c, which is formed between
the relief 25 and the upper cutting edge 21a, and a corner 21d,
which is formed between the relief 25 and the side cutting edge
21b, are both chamfered. When the inner blade 21 is inserted into
the outer blade 11, the chamfered corners 21c and 21d prevent the
side cutting edge 21b of the inner blade 21 from getting caught in
the side wall 11a of the outer blade 11. This facilitates the
insertion of the inner blade 21 into the outer blade 11.
Dimensional errors in the inner blade 21 and outer blade 11 may
cause the upper cutting edge 21a or side cutting edge 21b of the
inner blade 21 to project relatively out of the curved bend 11b of
the outer blade 11. Even in such a case, the chamfered corners 21c
and 21d suppress interference between the bend 11b and the cutting
edges 21a and 21b and minimize the influence of dimensional errors
in the inner blade 21 and outer blade 11.
[0033] A corner 21j in the relief 25 is curved. This increases the
strength of the corner 21j and prevents deformation and damage of
the inner blade 21.
[0034] The inner blade 21 further includes side sliding portions
21e and 21f facing toward the side wall 11a of the outer blade 11.
The side sliding portion 21e is continuous with the side cutting
edge 21b, and the side sliding portion 21f is spaced apart by a
predetermined distance from the side sliding portion 21e. In the
illustrated example, each of the side sliding portions 21e and 21f
are straight projections. The inner blade 21 includes an upper arm
21g and a lower arm 21h, which project in a direction opposite to
the side cutting edge 21b. The upper arm 21g and the lower arm 21h
are fitted into an inner blade fitting hole 22a formed in the inner
blade frame 22. The sideward pushing spring 23, which is formed by
a single wire spring, is mounted on the inner blade frame 22. The
sideward pushing spring 23 has an abutment portion 23a, which abuts
against the inner blade 21. The elastic force of the sideward
pushing spring 23 pushes the inner blade 21 outward in the radial
direction against the inner surface of the side wall 11a of the
outer blade 11. Thus, as the inner blade 21 receives the elastic
force of the sideward pushing spring 23, the two side sliding
portions 21e and 21f slide along the inner surface of the outer
blade 11. In this manner, the inner blade 21 stably slides along
the side wall 11a of the outer blade 11 while preventing the side
cutting edge 21b from projecting into the slits 11d.
[0035] The upper part of the inner blade 21 includes a bent piece
21i, which is inclined relative to the radial direction and bent in
the circumferential direction. The bent piece 21i has a width W1,
which is the distance between the circumferential positions of the
radially basal and distal ends of the bent piece 21i. The width W1
is set to be greater than the width W2 of the slits 11d of the
outer blade 11. In the illustrated example, the upward pushing
spring 24, which is a coil spring, is accommodated in a lower
cavity 22b (refer to FIG. 5) of the inner blade frame 22. Thus, the
upward pushing spring 24 is arranged between the inner blade frame
22 and the joint 5. The elastic force of the upward pushing spring
24 pushes the inner blade 21 in the upper direction against the
inner surface of the upper surface 11c of the outer blade 11. Thus,
as the inner blade 21 receives the elastic force of the upward
pushing spring 24, the bent piece 21i slides along the inner
surface of the upper wall 11c of the outer blade 11. In this
manner, the inner blade 21 slides along the upper wall 11c and the
side wall 11a of the outer blade 11, while preventing the upper
cutting edges 21a from projecting into the slits 11d.
[0036] In this manner, the outer blade block 10 and the inner blade
block 20 form the blade unit 1 of the nose hair trimmer according
to the present embodiment. This clips nose hair with the outer
blade 11 and the inner blade 21 in a satisfactory manner.
[0037] The structures of the outer blade 11 and the inner blades 21
may be described in the following manner. The outer blade 11
includes a plurality of teeth formed by the slits 11d. Each tooth
includes a basal portion, a distal portion, and a bent portion. The
basal portion extends upward substantially parallel to the center
axis of the outer blade 11 (e.g., rotation axis L1). The distal
portion extends inward toward the center axis of the outer blade
11. The bent portion is curved and located between the basal
portion and the distal portion. A straight edge, or the upper
cutting edge 11e, is formed on the distal portion, and a straight
edge, or the side cutting edge 11f, is formed on the basal portion.
Each inner blade 21 includes the upper cutting edge 21a, the side
cutting edge 21b, and the relief 25. The upper cutting edge 21a is
a straight edge formed at a location corresponding to the upper
cutting edge 11e of the outer blade 11. The side cutting edge 21b
is a straight edge formed at a location corresponding to the side
cutting edge 11f of the outer blade 11. The relief 25 is a cutout
portion formed at a location corresponding to the bend 11b of the
outer blade 11. The relief 25 of the inner blade 21 does not
contact the outer blade 11. The inner blade 21 contacts the outer
blade 11 only with its straight portions, which include the upper
cutting edge 21a and the side cutting edge 21b. Thus, the inner
blades 21 rotate smoothly and reduce noise, while improving the
clipping capability.
[0038] The present embodiment has the advantages described
below.
[0039] (1) In the present embodiment, the outer blade 11 includes
the cylindrical side wall 11a, the upper wall 11c, and the curved
bend 11b, which connects the side wall 11a and the upper wall 11c.
The outer blade 11 includes the straight upper cutting edges 11e
and side cutting edges 11f formed by the slits 11d extending from
the upper wall 11c to the upper part of the side wall 11a. Each
inner blade 21 includes the straight upper cutting edge 21a, which
corresponds to the upper cutting edges 11e of the outer blade 11,
and the straight side cutting edge 21b, which corresponds to the
side cutting edges 11f of the outer blade 11. The outer blade 11
and the inner blade 21 clip nose hair with the straight side
cutting edges 11f and 21b and the straight upper cutting edges 11e
and 21a. In addition to the side cutting edges 11f and 21b, the
nose hair trimmer includes the straight upper cutting edges 11e and
21a. The straight cutting edges 11f, 11e, 21a, and 21b allow for
the shapes of the outer blade 11 and the inner blades 21 to be in
conformance more easily than when they are curved. This decreases
interference between the outer blade 11 and the inner blades 21 and
suppresses the production of noise. Further, the pressure applied
by the inner blades 21 to the outer blade 11 becomes stable and
allows for satisfactory clipping of nose hair. This improves the
clipping capability.
[0040] (2) In the present embodiment, in the outer blade 11 and the
inner blades 21, each of the upper cutting edges 11e and 21a are
formed to extend straight and orthogonal to the rotation axis L1 of
the inner blades 21. This facilitates formation of the outer blade
11 and the inner blade 21 and simplifies contact of the inner blade
21 with the outer blade 11.
[0041] (3) The outer blade 11 includes the eight (even number)
slits 11d, which are arranged at equal angular intervals. Thus, by
moving the grindstone 13 past the center of the circular upper wall
11c of the outer blade 11, which is cylindrical, two slits 11d may
be formed at the same time. When an odd number of slits 11d are
provided, the slits 11d are formed one at a time. Thus, the even
number of slits 11d allows for the slits 11d to be formed within a
short period of time. In particular, when there are eight slits
11d, this ensures that the slits 11d have the width W2 that is
suitable for receiving nose hair (refer to FIG. 6), while the outer
blade 11 is held with its diameter remaining suitable for insertion
into a user's nostril. Thus, nose hair is further effectively
clipped when there are eight slits 11d.
[0042] (4) In the present embodiment, to prevent contact between
the outer blade 11 and the inner blades 21 at curved portions, each
inner blade 21 includes the relief 25, which is arranged at a
location corresponding to the curved bend 11b of the outer blade
11. Due to the relief 25, the inner blades 21 and the outer blade
11 are in contact with each other only at straight portions and not
at curved portions. This further effectively suppresses the
production of noise.
[0043] (5) In the present embodiment, the relief 25 is a tetragonal
cutout portion formed at a location corresponding to the curved
bend 11b of the outer blade 11 in the inner blade 21. Thus, noise
may be suppressed just by slightly changing the shape of the inner
blade 21.
[0044] (6) In the present embodiment, each inner blade 21 includes
the chamfered corner 21c, which is arranged between the relief 25
and the upper cutting edge 21a, and the chamfered corner 21d, which
is arranged between the relief 25 and the side cutting edge 21b.
Thus, when the inner blade 21 is inserted into the outer blade 11,
the chamfered corners 21c and 21d prevent the side cutting edges
21b of the inner blades 21 from getting caught in the side wall 11a
of the outer blade 11. This facilitates the insertion of the inner
blade 21 into the outer blade 11. Further, even when dimensional
errors in the inner blade 21 and outer blade 11 cause the upper
cutting edges 21a or side cutting edges 21b of the inner blades 21
to project relatively out of the curved bend 11b of the outer blade
11, the chamfered corners 21c and 21d suppress interference between
the bend 11b and the cutting edges 21a and 21b and minimize the
influence of dimensional errors in the inner blade 21 and outer
blade 11.
[0045] (7) In the present embodiment, the width W1 of the bent
piece 21i formed on the upper part of each inner blade 21 is
greater than the width W2 of the slits 11d of the outer blade 11.
This prevents the upper cutting edges 21a of the inner blades 21
from projecting into the slits 11d and thereby prevents damaging of
the inner blades 21 and the like. Further, the bent piece 21i may
easily be formed by just bending part of the corresponding inner
blade 21.
[0046] The present examples and embodiments are to be considered as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein, but may be modified within the
scope and equivalence of the appended claims.
[0047] In the above-discussed embodiment, the sideward pushing
spring 23, which is formed by a single wire spring, pushes the
inner blades 21 against the side wall 11a of the outer blade 11.
However, the means for urging the inner blades 21 is not limited to
the sideward pushing spring 23. For example, as shown in FIG. 8, a
typical coil spring 30 may be used to push the inner blades 21
against the side wall 11a of the outer blade 11.
[0048] In the above-discussed embodiment, the upper cutting edge
21a and side cutting edge 21b are each formed integrally with the
corresponding inner blade 21. Instead, for example, as shown in
FIG. 9, each inner blade 21 may include an upper inner blade 40,
which includes the upper cutting edge 21a, and a side inner blade
41, which includes the side cutting edge 21b. In this case, the
upper cutting edge 21a and the side cutting edge 21b are formed by
discrete bodies. Thus, in comparison to when the upper cutting edge
21a and the side cutting edge 21b are formed integrally with the
corresponding inner blade 21, the influence of differences in the
dimensions and shapes of the upper cutting edges 21a and the side
cutting edges 21b is minimized. As a result, the inner blades 21
slide in a preferable manner along the outer blade 11. Further, in
this structure, the width W1 of the upper part (upper cutting edge
21a) of the inner blade 21 is greater than the width W2 of the
slits 11d in the outer blade 11. This prevents the upper cutting
edges 21a of the inner blades 21 from projecting into the slits 11d
of the outer blade 11 and thereby prevents damaging of the inner
blades 21 and the like.
[0049] In the above-discussed embodiment, the inner blade 21
includes a tetragonal cutout portion that forms the relief 25.
However, as shown in FIG. 10(a), for example, the portion in the
inner blade 21 that corresponds to the bend 11b of the outer blade
may be beveled to form a relief 25a. Further, as shown in FIGS.
10(b) to 10(d), the portion of the inner blade 21 between the upper
cutting edge 21a and side cutting edge 21b may be curved. In this
case, the portion in the outer blade 11 between the upper wall 11c
and the side wall 11a may form an orthogonal relief 11h, a
trapezoidal relief 11i, or a thinned relief 11j. Alternatively, the
inner blade 21 and the outer blade 11 may both include a
relief.
[0050] In the above-discussed embodiment, the structure and shape
of the inner blade 21 and outer blade 11 may be changed as
required.
[0051] In the above-discussed embodiment, the outer blade 11
includes eight slits 11d. However, the outer blade 11 may include
any other number of slits 11d although it is desirable that there
be an even number of slits 11d to facilitate formation.
[0052] Although not particularly mentioned above, the battery may
be a primary battery, such as a dry cell, or a rechargeable
secondary battery.
[0053] The present examples and embodiments are to be considered as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein, but may be modified within the
scope and equivalence of the appended claims.
* * * * *